PURPOSE: To set the detection level of an input signal freely without causing deterioration in operation margin nor a failure in operation by providing fuses as nonvolatile data storage elements and varying the value of a reference voltage according to the states of those fuses.

CONSTITUTION: Four resistances R11WR14 in a voltage dividing circuit 50 are set to proper values and then fuses 52W54 are cut selectively to obtain up to seven different values as the reference voltage VREF. For example, the output voltage of the voltage dividing circuit 50, i.e. the value of the reference voltage VREF is varied into seven kinds according to stored data corresponding to the states of the fuses 54W54 as nonvolatile data storage elements. Consequently, even if the reference voltage VREF itself varies owing to variance, etc., generated in a manufacturing process or when the circuit balance state of a sense circuit 20 is lost, the value of the reference voltage VREF is varied correspondingly and the detection level of the sense circuit 20 is made coincident with a normal level.